human defence system Flashcards
list 6 non-specific defence systems of the body
-stomach
-trachea
-bronchi
-nose
-tears
-skin
how does the skin protect against pathogens?
acts as a barrier to stop the pathogens from entering, secretes antimicrobial substances which kill pathogens, formation of scabs after skin has been cut
how does the nose protect against pathogens?
contains hair and mucus which trap particles that could contain pathogens, preventing them from entering the lungs
how does the trachea/bronchi protect against pathogens?
secrete mucus to trap pathogens, lined with cilia (hair-like substances) which waft the mucus with trapped pathogens up to the back of the throat to be swallowed
how does the eye protect against pathogens?
secretes tears which contain enzymes that kill pathogens
how does the stomach protect against pathogens?
produces hydrochloric acid which kills pathogens that have been swallowed
3 ways white blood cells defend against pathogens
-phagocytosis
-produce antibodies
-produce antitoxins
what cells defend against pathogens?
white blood cells
describe phagocytosis
white blood cells engulf pathogens and digest them
how does phagocytosis protect us?
destroys pathogens meaning they can’t make you ill anymore
describe the process of producing antibodies
-invading pathogens have unique antigens on its surface
-white blood cells come across foreign antigens and start to produce antibodies to lock onto the invading pathogens so they can be found and destroyed by other white blood cells
-antibodies specific to antigen
-antibodies then produced rapidly if the person is infected with the same pathogen
what are the white blood cells that produce antibodies called?
B-lymphocytes
how do antibodies protect you?
rapidly produced to help white blood cells find them and destroy them so are immune
describe producing antitoxins
release antitoxins which neutralise the toxins produced by bacteria by binding to them
how do antitoxins protect you?
neutralise toxins so you feel better
